Does polycythemia vera (PV) cause cold intolerance?

Does Polycythemia Vera Cause Cold Intolerance?

Polycythemia vera (PV) is not typically associated with cold intolerance as a primary symptom, and there is no evidence in current guidelines supporting cold intolerance as a characteristic manifestation of this myeloproliferative neoplasm.

Understanding Polycythemia Vera and Its Symptoms

Polycythemia vera is a chronic myeloproliferative neoplasm characterized by:

• Increased red blood cell mass (erythrocytosis)
• Often accompanied by leukocytosis and thrombocytosis
• Associated with JAK2 mutations (V617F or exon 12) in almost all cases 1

Common Symptoms and Manifestations

The primary symptoms and complications of PV include:

1. Hyperviscosity-related symptoms:

   • Headache
   • Light-headedness
   • Transient neurologic or ocular disturbances
   • Tinnitus
   • Atypical chest discomfort
   • Paresthesias 2

2. Pruritus (itching):

   • Documented in approximately 48% of patients either at diagnosis or later
   • Can be severe enough to cause sleep deprivation
   • Often described as the most agonizing aspect of PV for affected patients 2

3. Microvascular disturbances:

   • Erythromelalgia (painful burning sensation of hands/feet with erythema and warmth)
   • Occurs in approximately 3% of PV patients 2

4. Other common manifestations:

   • Splenomegaly
   • Thrombotic complications (arterial and venous)
   • Hemorrhagic events
   • Constitutional symptoms (fatigue, weight loss)
   • Risk of progression to myelofibrosis or acute leukemia 1, 3

Cold Intolerance and PV

The comprehensive Mayo Clinic review of polycythemia vera does not list cold intolerance among the recognized symptoms or complications of the disease 2. Similarly, the more recent guidelines and reviews do not mention cold intolerance as a feature of PV 4, 1, 3, 5, 6.

Potential Mechanisms Related to Temperature Sensitivity

While cold intolerance is not specifically documented as a PV symptom, there are several aspects of the disease that could theoretically affect temperature regulation:

1. Blood viscosity changes:

   • PV increases blood viscosity, especially at low shear rates
   • This affects blood flow dynamics, which could potentially impact peripheral circulation 2

2. Microvascular disturbances:

   • PV is associated with platelet-mediated arteriolar inflammation
   • These microcirculatory changes primarily manifest as erythromelalgia (heat and burning sensation) rather than cold intolerance 2

Clinical Implications

When evaluating a patient with PV who reports cold intolerance:

1. Consider alternative causes:

   • Thyroid dysfunction (hypothyroidism)
   • Anemia (which would be paradoxical in PV but could occur with iron deficiency from frequent phlebotomies)
   • Peripheral vascular disease
   • Raynaud's phenomenon

2. Assess for iron deficiency:

   • Repetitive phlebotomies in PV treatment can deplete iron stores
   • This may result in iron-deficient red blood cells with reduced oxygen-carrying capacity 4
   • Iron deficiency has been associated with temperature regulation issues in some patients

3. Monitor treatment effects:

   • Phlebotomy is a cornerstone of PV management to maintain hematocrit <45% in men
   • Regular monitoring of hematological parameters is essential 4

Management Considerations

The management of PV focuses on:

1. Reducing thrombotic risk:

   • Therapeutic phlebotomy to maintain hematocrit <45% in men
   • Low-dose aspirin (81-100 mg daily) unless contraindicated
   • Cytoreductive therapy for high-risk patients 4, 5

2. Symptom management:

   • For pruritus: antihistamines, selective serotonin reuptake inhibitors, interferon-α
   • For erythromelalgia: low-dose aspirin 2

If a PV patient experiences cold intolerance, it would be prudent to:

• Evaluate for iron deficiency from phlebotomy therapy
• Consider thyroid function testing to rule out comorbid hypothyroidism
• Assess peripheral circulation and rule out other causes of cold sensitivity

In conclusion, while PV causes numerous symptoms related to hyperviscosity and microvascular disturbances, cold intolerance is not established as a characteristic manifestation of the disease based on current medical literature and guidelines.